In a series or flow production, workpieces are typically transported through individual stations in succession, wherein the workpiece is subjected to a variety of work processes in these stations. In particular in automotive construction, vehicle bodies are transported through a large number of processing stations, in which a variety of processes, such as a welding process for example, are carried out. The workpieces are usually conveyed continuously through production or assembly, whereby the workpieces are frequently processed in a flow operation, i.e. as they are being transported.
In automotive construction, the vehicle bodies are often conveyed through production or assembly in a suspended manner in so-called c-shaped hangers, while being processed, for example, by fitters. At present, there is a low degree of automation in this type of production or assembly line, and a majority of the work is performed manually by workers or fitters. The advantage of this is that this type of manual activity can be accomplished with very high availability and the worker can apply his problem-solving logic, something that an automation system typically does not possess. A relatively high throughput can thus be kept largely constant.
Even though the use of manipulators or robots in such systems increases the accuracy and precision of the work to be performed, there are also disadvantages: On the one hand, the configuration is costly and the manipulators in the respective work station have to be calibrated. The use of manipulators in a flow production is therefore in particularly difficult in terms of their flexibility with respect to position and the work they are expected to perform. Since, in particular in automotive construction, the exact position of the individual bodies in a work station can vary, to make precise work of the manipulator possible, the exact position of the workpieces during operation must be determined as well. In addition, the use of manipulators increases the risk of injury to people, in particular when the manipulator is not (or only conditionally) suitable for use in a human-robot collaboration (HRC) environment. Finally, any occurring fault, such as an overload of a manipulator, usually triggers an emergency stop function. As a result the flow production is interrupted, which ultimately has a negative effect on throughput and revenue.
It is therefore an object of the present invention to make possible a flexible and easy implementation of manipulators in flow productions. The object is, in particular, to make an easy interchangeability of manipulators and/or work stations possible. The present invention is furthermore based on the object to provide a safe work station, in particular for flow production, with which possible interruptions in flow production are reduced.
This and other objects, which will become apparent when reading the following description, are achieved with a flow production system as described herein.